The Khumric Brythonic Legacy of Britain - AD 500 - AD 800

the more I look into this research, the more I'm finding (from all sorts of different sources) the fact that gold/silver/bronze/lead etc. mine-trading took place between Wales and the Mediterranean.

Now, remember, this sceptred isle is supposed to have been conquered by Rome in AD 43 or so and Britain was the outer north-western edge of the Roman Empire. But, did the Romans leave in AD 383-410 to consolidate their own failing footing in Europe or had the Britons' empire been growing throughout this so-called invasion and DID THE BRITONS KICK THEM OUT.

And who were these so-called Britons with a Coelbren Alphabet? And did Boudicca speak Welsh, or (the common language of) Ancient Welsh known as Khumric? And does Khumric link right back to the Cimmeroi or Syria/Turkey via the Altalntic-coastal route round the Pillars of Hercules or Malta aka Gateway to the Med? And how did all this Khumric-ness survive the (supposed) Roman invasion (and clerical transformation) of Britain?

Below, you'll see how the AD 500-800 story panned out; a massive Welsh territory being gradually eroded from the east by the incursions of the Anglo-Saxons then the Danes then the Normans, isolating the (northern) Cumbrians from the (western) Cymru and the southern (Cornish).